"use client";

import { useEffect } from "react";

// Registers the offline service worker (public/sw.js) after load. Rendered once
// in the root layout. No-op where service workers are unavailable (older
// browsers, insecure origins) — the site still works online-only.
export function ServiceWorkerRegister() {
  useEffect(() => {
    // Only register in production builds. A SW caching assets/data in dev fights
    // hot-reload and the e2e suite's request mocking; the deployed static export
    // is where offline support matters.
    if (process.env.NODE_ENV !== "production") return;
    if (typeof navigator === "undefined" || !("serviceWorker" in navigator)) {
      return;
    }
    const register = () => {
      navigator.serviceWorker.register("/sw.js").catch(() => {
        // Registration failures are non-fatal (e.g. SW disabled) — stay online.
      });
    };
    if (document.readyState === "complete") register();
    else {
      window.addEventListener("load", register, { once: true });
      return () => window.removeEventListener("load", register);
    }
  }, []);
  return null;
}